In cases where the payor parent's adjusted gross income is below $2,600 per month, an additional calculation in Worksheet A, Part II, §48-13-403 of this code, shall be made. This additional calculation sets the child support order at whichever is lower.

1. (1) Child support at the amount determined in Worksheet A, Part I, §48-13-403 of this code; or
2. (2) The difference between 80 percent of the payor parent's adjusted gross income and $997, or $50, whichever is more.